Polymers of acrylic and like acids, as well as salts thereof, have been used in the past as thickeners in diverse applications. Such polymers are generally homopolymers of an acrylic acid or copolymers thereof with a small amount of a comonomer as well as a small amount of a crosslinking agent. In aqueous or in alkaline environments, such polymers exhibit flat viscosity characteristic and do not impart the ability to vent gases entrapped or internally generated. As thickeners, such polymers are prepared in powder form having particle size on the order of 1 to 10 microns. The small particle size of the polymers may reflect the inability of compositions containing such thickeners to vent gases.